Co-teaching is an instructional strategy for pairing special education and general education teachers to provide specially designed instruction to students with disabilities in general education settings. Instructional coaching is a professional development model that can provide co-teachers with additional strategies to effectively educate special and general education students in their classes. This type of professional development can also influence co-teacher perceptions and mindsets about co-teaching. This study examined the relationships between co-teacher instructional coaching and co-teacher growth mindsets. This mixed methods study, utilizing an explanatory sequential design, analyzed the relationship between instructional coaching and co-teacher perceptions of growth mindset. Special education and general education co-teachers (grades k - 8) from a suburban school district located in the northeastern United States participated in this study. This study examined the growth mindsets of co-teachers to determine if differences existed between co-teachers who have received instructional coaching and those who have not. This study provides school administrators with information about the mindsets of co-teachers, allowing administrators to consider instructional coaching as a vehicle for changing teachers' mindsets and for improving the academic achievement of special education students. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]